2 * linux/kernel/power/user.c
4 * This file provides the user space interface for software suspend/resume.
6 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
8 * This file is released under the GPLv2.
12 #include <linux/suspend.h>
13 #include <linux/syscalls.h>
14 #include <linux/reboot.h>
15 #include <linux/string.h>
16 #include <linux/device.h>
17 #include <linux/miscdevice.h>
19 #include <linux/swap.h>
20 #include <linux/swapops.h>
23 #include <linux/console.h>
24 #include <linux/cpu.h>
25 #include <linux/freezer.h>
27 #include <asm/uaccess.h>
31 #define SNAPSHOT_MINOR 231
33 static struct snapshot_data
{
34 struct snapshot_handle handle
;
39 char platform_suspend
;
42 atomic_t snapshot_device_available
= ATOMIC_INIT(1);
44 static int snapshot_open(struct inode
*inode
, struct file
*filp
)
46 struct snapshot_data
*data
;
48 if (!atomic_add_unless(&snapshot_device_available
, -1, 0))
51 if ((filp
->f_flags
& O_ACCMODE
) == O_RDWR
) {
52 atomic_inc(&snapshot_device_available
);
55 if(create_basic_memory_bitmaps()) {
56 atomic_inc(&snapshot_device_available
);
59 nonseekable_open(inode
, filp
);
60 data
= &snapshot_state
;
61 filp
->private_data
= data
;
62 memset(&data
->handle
, 0, sizeof(struct snapshot_handle
));
63 if ((filp
->f_flags
& O_ACCMODE
) == O_RDONLY
) {
64 data
->swap
= swsusp_resume_device
?
65 swap_type_of(swsusp_resume_device
, 0, NULL
) : -1;
66 data
->mode
= O_RDONLY
;
69 data
->mode
= O_WRONLY
;
73 data
->platform_suspend
= 0;
78 static int snapshot_release(struct inode
*inode
, struct file
*filp
)
80 struct snapshot_data
*data
;
83 free_basic_memory_bitmaps();
84 data
= filp
->private_data
;
85 free_all_swap_pages(data
->swap
);
87 mutex_lock(&pm_mutex
);
89 mutex_unlock(&pm_mutex
);
91 atomic_inc(&snapshot_device_available
);
95 static ssize_t
snapshot_read(struct file
*filp
, char __user
*buf
,
96 size_t count
, loff_t
*offp
)
98 struct snapshot_data
*data
;
101 data
= filp
->private_data
;
102 res
= snapshot_read_next(&data
->handle
, count
);
104 if (copy_to_user(buf
, data_of(data
->handle
), res
))
107 *offp
= data
->handle
.offset
;
112 static ssize_t
snapshot_write(struct file
*filp
, const char __user
*buf
,
113 size_t count
, loff_t
*offp
)
115 struct snapshot_data
*data
;
118 data
= filp
->private_data
;
119 res
= snapshot_write_next(&data
->handle
, count
);
121 if (copy_from_user(data_of(data
->handle
), buf
, res
))
124 *offp
= data
->handle
.offset
;
129 static inline int platform_prepare(void)
134 error
= hibernation_ops
->prepare();
139 static inline void platform_finish(void)
142 hibernation_ops
->finish();
145 static inline int snapshot_suspend(int platform_suspend
)
149 mutex_lock(&pm_mutex
);
150 /* Free memory before shutting down devices. */
151 error
= swsusp_shrink_memory();
155 if (platform_suspend
) {
156 error
= platform_prepare();
161 error
= device_suspend(PMSG_FREEZE
);
165 error
= disable_nonboot_cpus();
168 error
= swsusp_suspend();
170 enable_nonboot_cpus();
172 if (platform_suspend
)
178 mutex_unlock(&pm_mutex
);
182 static inline int snapshot_restore(int platform_suspend
)
186 mutex_lock(&pm_mutex
);
187 pm_prepare_console();
188 if (platform_suspend
) {
189 error
= platform_prepare();
194 error
= device_suspend(PMSG_PRETHAW
);
198 error
= disable_nonboot_cpus();
200 error
= swsusp_resume();
202 enable_nonboot_cpus();
204 if (platform_suspend
)
210 pm_restore_console();
211 mutex_unlock(&pm_mutex
);
215 static int snapshot_ioctl(struct inode
*inode
, struct file
*filp
,
216 unsigned int cmd
, unsigned long arg
)
219 struct snapshot_data
*data
;
223 if (_IOC_TYPE(cmd
) != SNAPSHOT_IOC_MAGIC
)
225 if (_IOC_NR(cmd
) > SNAPSHOT_IOC_MAXNR
)
227 if (!capable(CAP_SYS_ADMIN
))
230 data
= filp
->private_data
;
234 case SNAPSHOT_FREEZE
:
237 mutex_lock(&pm_mutex
);
238 if (freeze_processes()) {
242 mutex_unlock(&pm_mutex
);
247 case SNAPSHOT_UNFREEZE
:
250 mutex_lock(&pm_mutex
);
252 mutex_unlock(&pm_mutex
);
256 case SNAPSHOT_ATOMIC_SNAPSHOT
:
257 if (data
->mode
!= O_RDONLY
|| !data
->frozen
|| data
->ready
) {
261 error
= snapshot_suspend(data
->platform_suspend
);
263 error
= put_user(in_suspend
, (unsigned int __user
*)arg
);
268 case SNAPSHOT_ATOMIC_RESTORE
:
269 snapshot_write_finalize(&data
->handle
);
270 if (data
->mode
!= O_WRONLY
|| !data
->frozen
||
271 !snapshot_image_loaded(&data
->handle
)) {
275 error
= snapshot_restore(data
->platform_suspend
);
280 memset(&data
->handle
, 0, sizeof(struct snapshot_handle
));
284 case SNAPSHOT_SET_IMAGE_SIZE
:
288 case SNAPSHOT_AVAIL_SWAP
:
289 avail
= count_swap_pages(data
->swap
, 1);
290 avail
<<= PAGE_SHIFT
;
291 error
= put_user(avail
, (loff_t __user
*)arg
);
294 case SNAPSHOT_GET_SWAP_PAGE
:
295 if (data
->swap
< 0 || data
->swap
>= MAX_SWAPFILES
) {
299 offset
= alloc_swapdev_block(data
->swap
);
301 offset
<<= PAGE_SHIFT
;
302 error
= put_user(offset
, (sector_t __user
*)arg
);
308 case SNAPSHOT_FREE_SWAP_PAGES
:
309 if (data
->swap
< 0 || data
->swap
>= MAX_SWAPFILES
) {
313 free_all_swap_pages(data
->swap
);
316 case SNAPSHOT_SET_SWAP_FILE
:
317 if (!swsusp_swap_in_use()) {
319 * User space encodes device types as two-byte values,
320 * so we need to recode them
322 if (old_decode_dev(arg
)) {
323 data
->swap
= swap_type_of(old_decode_dev(arg
),
347 if (!mutex_trylock(&pm_mutex
)) {
352 if (pm_ops
->prepare
) {
353 error
= pm_ops
->prepare(PM_SUSPEND_MEM
);
358 /* Put devices to sleep */
360 error
= device_suspend(PMSG_SUSPEND
);
362 printk(KERN_ERR
"Failed to suspend some devices.\n");
364 error
= disable_nonboot_cpus();
366 /* Enter S3, system is already frozen */
367 suspend_enter(PM_SUSPEND_MEM
);
368 enable_nonboot_cpus();
370 /* Wake up devices */
375 pm_ops
->finish(PM_SUSPEND_MEM
);
378 mutex_unlock(&pm_mutex
);
387 if (hibernation_ops
) {
388 data
->platform_suspend
= 1;
396 if (data
->platform_suspend
) {
397 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK
);
398 error
= hibernation_ops
->enter();
403 if (data
->platform_suspend
)
409 printk(KERN_ERR
"SNAPSHOT_PMOPS: invalid argument %ld\n", arg
);
414 case SNAPSHOT_SET_SWAP_AREA
:
415 if (swsusp_swap_in_use()) {
418 struct resume_swap_area swap_area
;
421 error
= copy_from_user(&swap_area
, (void __user
*)arg
,
422 sizeof(struct resume_swap_area
));
429 * User space encodes device types as two-byte values,
430 * so we need to recode them
432 swdev
= old_decode_dev(swap_area
.dev
);
434 offset
= swap_area
.offset
;
435 data
->swap
= swap_type_of(swdev
, offset
, NULL
);
453 static const struct file_operations snapshot_fops
= {
454 .open
= snapshot_open
,
455 .release
= snapshot_release
,
456 .read
= snapshot_read
,
457 .write
= snapshot_write
,
459 .ioctl
= snapshot_ioctl
,
462 static struct miscdevice snapshot_device
= {
463 .minor
= SNAPSHOT_MINOR
,
465 .fops
= &snapshot_fops
,
468 static int __init
snapshot_device_init(void)
470 return misc_register(&snapshot_device
);
473 device_initcall(snapshot_device_init
);